Calibrating electric meters.



0. T. BLATHY.

CALIBRATING ELECTRIC METERS. APPLICATION FILED 0.20.15.191

Patented ApnlO, 1917.

2 SHEETS-SHEET I.

//VV/VTOR 0770 TBLA'THY MQMW/ 0. T. BL/(THY.

CALIBRATING ELECTRIC METERS.

APPLICATION FILED 05c. 15. 1914.

2 SHEETS-SHEET 2.

Ari-08am) Patented Apr. 10, 1917.

or'ro TITUS BLATHY, or BUDAPEST, HUNGARY.

CALIBRATING ELECTRIC METERS.

Specification of Letters Patent.-

Patented Apr. 10, 191W.

Application filed December 15, 1914. Serial No. 877,419.

To all whom it may concern:

Be it known that I, OTTO TrrUs BLri'rrIY, a subject of the King of Hungary,res1d1ng at Budapest, in the Kingdom of Hungary, have invented new and useful Improvements in Calibrating Electric Meters; and I do hereby declare the followingto be a full, clear, and exact description of the same.

The adjustment of electricity-meters by varying the strength of the braking field was hitherto obtained by a displacement of the braking magnets. With the object of avoiding the disadvantages of th s method 1t has been proposed to employ a magnetic shunt and to vary either the sectional area of the shunt member or its distance from the magnet coilsuntil the desired strength of the braking field was reached. Compared with this method the present'invention represents a simplification, as it allows of performing the adjustment of the strength of the braking field, both without changing the fixed position of the braking magnets and without providing magnetic shunts.

According to the present invention a device is provided by. means of which the branches of the magnet may be spread more or less far apart from each other or be approached to each other respectively, in order to vary the relative distance between the two pole surfaces of the magnet.

Preferably this distancing device is dis posed between the two branches of the braking magnet so that the adjustment of the braking magnets may be performed before the magnets are fitted into the meter, and the braking magnets will retain their adjust- 111185113, even after the meter has been dismante As such distancing device sccrews or wedges may be employed, which are preferably disposed as close as possible to the pole surfaces, for example, between the pole surfaces, or also between lugs on the poles of the braking magnet.

In the accompanying drawing several embodiments of the present invention are shown for ex emplification.

Figure 1 is a side elevation. Fig. 2 is a plan of the one embodiment, in which the distancing screws are disposed independent of the braking magnet.

.Fig. 3 is a side elevation of an embodiment in which the distancing screw acts on the two branches of the magnet.

Fig. t is an embodiment, shown in perspective View, in which the distancing screw acts between the pole surfaces of the braking magnet.

. Fig. 5 is a modification of the embodiment according to Fig. 4; in end'view.

Figs. 6 and 7- are end view and side elevation respectively of an embodiment in which a wedge is employed as distancing device.

Fig. 8 is a horizontal section on the line 8-8 in Fig. 6, and Fig. 9 is a side elevation of the same embodiment, with the tool for adjusting the Wedge attached.

In Figs. 1 and 2 the reference letter M indicates the braking magnet, which is secured with its lower branch 11, to the carrier A and,

acts on the braking disk 3 of the meter. The distancing device in this embodiment consists of a screw-m which is screwed into a female thread in the carrier A next tothe braking magnet and close to its poles in sucha manner, that the head of the screw 00 bears against the upper side of the upper branch m of the magnet. When the screw is screwed down, the-head of said screw will force the branch m ofthe magnet downward,

and this branch m will elastically yield within the range of the desired adjustment, so

that the pole surfaces of the magnet are approached toward each other and the strength of the braking field is intensified. For adjusting the meter the screw is screwed down so faruntil the meter runs synchronously with a standard meter. The braking magnet is so dimensioned that at the distance,

which the pole surfaces assume, when thedistancing device is disengaged, the magnet is somewhat too weak, so that the adjustment will always have to be obtained by intensifying the strength of the braking field. With this arrangementthe braking magnet must be adjusted after it has been fitted into the meter, and will have to be repeated when the meter is dismantled.

However, when the distancing device is disposed between the two branches of the braking magnet, the magnet will retain the adjustment, when once adjusted, so that such adjustment may be performed before the magnet is fitted into the'meter, and need neither be repeated when the meter is dismanent." 7 4 According to Fig. 3 the distancing screw 00 fits loosely in a bore in the one branch of the magnet m and screws in a female thread in the other branch of the magnet n, so that when the screw :v is screwed down, the two branches of the magnet, m and a re- *speetively are approached to each other. v

According to Fig. 4 the screw as disposed between the branches of the magnet .is situated close to the poles of the steelmagnet M and screws in a threaded bore in the branch m of the magnet, bearing with its end against the ole surface of the other branch n, so that w en the screw w is screwed down, the two branches m and n of the steel magnet are spread apart and will yield by their elasticity. Thereby the air gap between the poles of the magnet M is enlarged and the field acting on the braking disk 8 of the meter is reduced. With this arrangement the braking magnets must be somewhat stronger than is necessary for obtaining the desired braking efi'ect.

According to Fig. 5 lugs a and b are pro- I vided close to the poles of the magnet. The

distancing screw as is screwed through a .female thread in the one lug a and bears against the other lug b.

In place of a screw also wedges may be employed for spreading the two branches on and n of. the magnet apart, as illustrated in Figs. 6 and 7. Here a Wedge y is driven into conical grooves e in the pole surfaces,

whereby the two branches m and n of the magnet are forced apart.

For driving in the wedge by the exact distance required a screw-jack c, d may be employed (see Figs. 8 and 9). -The bow 0 of the screw-jack is fitted on the vertical mantled, as such an adjustment remains perand accurate manner.

What I claim as my invention, and desire to secure by Letters Patent of the United States, is:

1. An electric meter having a rotating part; a brake disk mounted on said rotatable part; a permanent magnet between the pole pieces of which said disk revolves; and

a screw engaging both legs of the magnet and adapted to regulate the distance between the pole surfaces more or less owing to the resiliency of the magnet.

2. An electric meter having a rotating part; a brake disk mounted on said rotatable part; an easily removable permanent magnet between the pole pieces of which said disk revolves; and a screw engaging both legs of the magnet and adapted to regulate the distance between the pole surfaces more or less. 1

In testimony whereof, I havesigned my name to this specification in the presence of two subscribing witnesses.

OTTO TITUS BLATHY.

Witnesses EUGEN HANSAUYE, EHREN STEIN WIR. 

